TST: groupby.apply assumed list of np.arrays had elements of equal len GH1738
BUG: groupby.apply assumed list of np.arrays had elements of equal len GH1735
Merge branch 'GH1738'

* GH1738:
  BUG: groupby.apply assumed list of np.arrays had elements of equal len GH1735
  TST: groupby.apply assumed list of np.arrays had elements of equal len GH1738
DOC: update RELEASE.rst